Heat-dissipating fan having dust-proof structure

ABSTRACT

A heat-dissipating fan having a dust-proof structure includes a stator and a rotor. The stator includes a shaft and a bearing disposed in a shaft hole of the shaft. The rotor includes an axle inserted in the bearing. The axle of the rotor has an inner end connected with an axle seat. The axle seat is located in the shaft hole of the shaft. A slight gap is defined between an outer wall of the axle seat and an inner wall of the shaft hole. The outer wall of the axle seat has a plurality of guiding grooves to block external air from entering the bearing. The guiding grooves are spiral grooves or V-shaped grooves. The guiding grooves are used to expel the air along with the rotation of the rotor, achieving a dust-proof protective structure in a non-contact type to block external dust or water vapor from entering the bearing to influence the running of the bearing. The present invention can enhance the service life of the heat-dissipating fan.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat-dissipating fan, and more particularly to a heat-dissipating fan having a dust-proof structure in a non-contact type.

2. Description of the Prior Art

Heat-dissipating fans are widely used on electronic products to solve the heat-dissipating problems, such as a CPU, a display card, a power supply, and the like. A conventional heat-dissipating fan comprises a stator and a rotor. An oil-retaining bearing is provided in a shaft hole of a shaft on a base of the stator. The stator includes an electromagnetic coil and silicon steel sheets fixed on the shaft. The rotator has an axle inserted in the oil-retaining bearing and a permanent magnetic ring fitted on the electromagnetic coil. When the fan is turned, the magnetic field of the electromagnetic coil and the magnetic ring drives the rotor to turn around the shaft. The blades of the rotator generate an air current to expel the heat from the electronic products so as to lower the temperature.

Although the conventional fan has the function to dissipate heat, there are some shortcomings existed in its structure and function when in use. In particular, there are gaps between the hub of the rotor and the base of the stator and between the top of the shaft and the bottom of the hub of the rotor, so external dust may enter the fan. After a period of time, the dust or water vapor will be accumulated in the fan to influence the running and the service life of the fan. Particularly, when the dust or water vapor enters the oil-retaining bearing, the fan cannot run smoothly or may malfunction.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a heat-dissipating fan having a dust-proof structure in a non-contact type to overcome the shortcomings of the prior art.

According to the present invention, there is provided a heat-dissipating fan having a dust-proof structure. The fan comprises a stator and a rotor. The stator comprises a shaft and a bearing disposed in a shaft hole of the shaft. The rotor includes an axle inserted in the bearing. The axle of the rotor has an inner end connected with an axle seat. The axle seat is located in the shaft hole of the shaft. A slight gap is defined between an outer wall of the axle seat and an inner wall of the shaft hole. The outer wall of the axle seat has a plurality of guiding grooves to block external air from entering the bearing. The guiding grooves are spiral grooves or V-shaped grooves. The guiding grooves are used to expel the air along with the rotation of the rotor, achieving a dust-proof protective structure in a non-contact type to block external dust or water vapor from entering the bearing to influence the running of the bearing. The present invention can enhance the service life of the heat-dissipating fan.

Preferably, the guiding grooves are spiral grooves.

Preferably, the guiding grooves are V-shaped grooves each including a first groove and a second groove. The first groove is adapted to compress air in the bearing inward. The second groove is adapted to expel external air. The first groove and the second groove are obliquely formed on the outer wall of the axle seat and have respective distal ends interconnected.

Compared to the prior art, the feature of the present invention is that the inner end of the axle of the rotor is connected with the axle seat and the outer wall of the axle seat is provided with the plurality of guiding grooves. The guiding grooves are used to expel the air along with the rotation of the rotor, achieving a dust-proof protective structure in a non-contact type to block external dust or water vapor from entering the bearing to influence the running of the bearing. The present invention can enhance the service life of the heat-dissipating fan.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a heat-dissipating fan according to a preferred embodiment of the present invention;

FIG. 2 is an enlarged view showing an axle and an axle seat having spiral grooves thereon according to the preferred embodiment of the present invention, and

FIG. 3 is an enlarged view showing an axle and an axle seat having V-shaped grooves thereon according to the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view showing a heat-dissipating fan according to a preferred embodiment of the present invention. The heat-dissipating fan comprises a stator 10 and a rotor 20. The stator 10 comprises a shaft 11 and a bearing 13 disposed in a shaft hole 12 of the shaft 11. The rotor 20 comprises an axle 21 which is inserted in the bearing 13.

Particularly, the axle 21 of the rotor 20 has an inner end connected with an axle seat 22. The axle seat 22 is located in the shaft hole 12 of the shaft 11. A slight gap is defined between an outer wall of the axle seat 22 and an inner wall of the shaft hole 12. The outer wall of the axle seat 22 has a plurality of guiding grooves 23 to expel the air in the bearing 13.

As shown in FIG. 2, the guiding grooves 23 are spiral grooves. When the rotor 20 is turned at a high speed, the spiral grooves are adapted to expel the air in the shaft hole 12 of the shaft 11 to form negative pressure in the shaft hole 12, preventing external dust or water vapor from entering the bearing 13 in the axle hole 12.

As shown in FIG. 3, the guiding grooves 23 are V-shaped grooves each including a first groove 231 and a second groove 232. The first groove 231 and the second groove 232 are obliquely formed on the outer wall of the axle seat 22 and have respective distal ends interconnected. The first groove 231 is used to compress the air in the shaft hole 12 inward, and the second groove 232 is used to expel external air, such that the junction of the first groove 231 and the second groove 232 forms lower pressure to block external dust or water vapor from entering the bearing 13 in the axle hole 12.

The feature of the present invention is that the inner end of the axle of the rotor is connected with the axle seat and the outer wall of the axle seat is provided with the plurality of guiding grooves. The guiding grooves are used to expel the air along with the rotation of the rotor, achieving a dust-proof protective structure in a non-contact type to block external dust or water vapor from entering the bearing to influence the running of the bearing. The present invention can enhance the service life of the heat-dissipating fan.

Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims. 

1. A heat-dissipating fan having a dust-proof structure, comprising a stator and a rotor, the stator comprising a shaft and a bearing disposed in a shaft hole of the shaft, the rotor comprising an axle inserted in the bearing, and characterized by: the axle of the rotor having an inner end connected with an axle seat, the axle seat being located in the shaft hole of the shaft, a gap defined between an outer wall of the axle seat and an inner wall of the shaft hole, the outer wall of the axle seat having a plurality of guiding grooves to expel air in the shaft hole.
 2. The heat-dissipating fan having a dust-proof structure as claimed in claim 1, wherein the guiding grooves are spiral grooves.
 3. The heat-dissipating fan having a dust-proof structure as claimed in claim 1, wherein the guiding grooves are V-shaped grooves each including a first groove and a second groove, the first groove being adapted to compress air in the bearing inward, the second groove being adapted to expel external air, the first groove and is the second groove being obliquely formed on the outer wall of the axle seat and having respective distal ends interconnected. 